The Printing of the Bible

Gutenberg experimented with printing single sheets of paper and even
small books, such as a simple textbook of Latin grammar, before
beginning his work on the Bible around 1450. In order to carry out
these projects, he would have had to invent a printing press and
develop a method of casting individual pieces of metal type.
Gutenberg's press was made out of wood and could have been modeled on
the winepresses used in the Rhineland vineyards or on the papermaker's
press. His type was made of a metal alloy which would melt at a fairly
low temperature but which could also stand up to being squeezed in a
press. It was long thought that Gutenberg had originated the
punch-matrix-mold system of typecasting used by typemakers for hundreds
of years, but very recent research has cast doubt on this theory. Quite
possibly Gutenberg used a cruder system, casting his metal types not in
re-usable molds, but in sand or some other unstable medium. In any
event, the process must have been a long and laborious one, since
nearly 300 different pieces of type are used in the Bible.

The handmade paper used by Gutenberg was of fine quality and was
imported from Italy. Each sheet contains a watermark, which may be seen
when the paper is held up to the light, left by the papermold. The two
watermark designs in the Texas copy are the grape cluster and the
bull's head (in Texas, we prefer to regard it as a longhorn steer's!).
Some copies of the Bible were printed on vellum (scraped calfskin).
Gutenberg's oil-based ink, made sufficiently thick enough to cling to
the type, is exceptionally black because of its high metal composition.

The number of presses in Gutenberg's shop is unknown, but the number
of pages he needed to print suggests that more than one press must have
been in use. A skilled typesetter selected the individual pieces of
type for each line of the text and set them in a frame (the forme),
which was placed on the bed of the press and then inked with
horsehair-stuffed balls. A sheet of paper was slightly moistened before
being placed over the forme, and then a stout pull by the pressman
completed the printing process.

No one knows exactly how many copies of the Bible were printed, but
the best guess is that around 180 -- 145 on paper and the rest on the
more luxurious and expensive vellum -- were produced. A contemporary
account by a visitor to Mainz indicates that the book was nearly ready
in October 1454 and available for sale by March 1455. Although the cost
of the book is not known, it would have been far too expensive even for
wealthy individuals, and so most copies were likely purchased by
churches and monasteries.